1. Field of the Invention
The present invention relates to an image processing apparatus capable of performing parallel processing with respect to print information using a multitasking function, a data processing method of the image processing apparatus, and a storage medium.
2. Description of the Related Art
The present invention relates to an image processing apparatus capable of performing parallel processing with respect to print information using a multitasking function, a data processing method of the image processing apparatus, and a program.
Recently, along with an improvement in processor technology, there has been an image processing apparatus which processes page description language (PDL) data at high-speed using multitask processing.
A conventional image processing system which interprets the PDL data and generates image formation bitmap data performs a process as described below. In general, in such an image forming process, the system interprets the PDL data, performs graphics processing, and generates intermediate data referred to as a display list (DL). The system then performs rendering, i.e., generates the image formation bitmap data using the intermediate data (refer to Japanese Patent Application Laid-Open No. 2004-268553).
Further, a control unit referred to as a master process divides a PDL data stream into two so that the PDL data operates in parallel. Sub-processes which are executed by two tasks then interpret the PDL data (refer to Japanese Patent Application Laid-Open No. 8-297560). The image processing apparatus thus performs parallel processing to interpret the PDL data, so that performance of PDL interpretation can be improved.
Furthermore, there is a technique in which an image processing apparatus realizes high-speed PDL interpretation by interpreting one piece of PDL data in parallel in a plurality of tasks. More specifically, the image processing apparatus divides the PDL data by a page, and distributes each of a plurality of the divided pages to each of a plurality of tasks. As a result of such division processing, the image processing apparatus can perform PDL interpretation in parallel using a plurality of resources such as a central processing unit (CPU) in the image forming processing apparatus. Usage efficiency of resources in the image forming processing apparatus is thus improved, and PDL interpretation can be performed at higher speed.
Communication between the image processing apparatus and a host apparatus is described below. Conventionally, data communication from a data processing apparatus on the host-side included in the image processing system depends on an operating system (OS). Currently, the system is created by utilizing a Windows® OS or a MacOS installed in the data processing apparatus.
In such a system environment, a first data processing apparatus corresponding to the Windows® system communicates with the image processing apparatus using a communication protocol such as transmission control protocol/Internet protocol (TCP/IP) as a data communication protocol. Further, a second data processing apparatus in the MacOS system communicates using a communication protocol such as AppleTalk®. The first and second data processing apparatuses communicate with the image processing apparatus as described below in performing printing using print information based on PDL, such as PostScript (PS (registered trademark)) as the print data.
For example, the first data processing apparatus transmits the print information based on PS to the image processing apparatus by one-way communication, and the image processing apparatus does not perform response processing. On the other hand, the second data processing apparatus transmits to the image processing apparatus the print information based on PS (i.e., PDL data) by bidirectional communication, and may receive a response from the image processing apparatus.